摘要:

AbstractThe fine structure of ox myocardial cells, as seen in transverse sections, is described. The presence of an extensive system of transverse tubules at Z region levels has been confirmed, the walls of the tubules being continuous with the sarcolemma.Preliminary observations in smaller animals indicate that similar tubules are readily seen in guinea‐pig myocardial cells and are present, but are more difficult to find, in the rat; communication between the tubules and the exterior is readily demonstrated in the guinea‐pig but less readily in the rat.Contact between the transverse tubules and the Z regions was not particularly close, and a thin delicate “circumferential Z tubule” was noted to lie round the myofibrils at most Z regions.The Z regions, on cross section, shows a tightly packed square array of filaments, double in number compared with the thin filaments seen elsewhere in the sarcomere; the appearances probably confirm for heart muscle the Z region structure which has been described for skeletal

ISSN:0002-9106    

DOI:10.1002/aja.1001170102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1965

数据来源: WILEY

摘要:

AbstractIn 50 lungs prepared as casts, the most common pattern of arrangement of the bronchial arteries, occurring in 30% of all lungs, was that of two posterior bronchial trunks to each side; next in frequency was the pattern of two trunks to the left and one to the right lung. In more than three‐fourths of all cases there were not more than two bronchial arteries on each side. In two‐thirds of the specimens various bronchial arteries arose both directly from the aorta and indirectly from an intercosto‐bronchial trunk. At least one intercosto‐bronchial trunk was present in 37 of the 50 specimens. All such trunks, even those supplying the left lung, took origin from the right side of the aorta, almost always from the first or second posterior segmental aortic branches, i.e., at the level of the fifth or sixth thoracic vertebra. Almost all intercosto‐bronchial trunks yielded a right bronchial artery. Approximately 84% of the left bronchial arteries sprang directly from the aorta. In 22% a single trunk was the source of all bronchial arteries to both lungs, and in 14% this trunk arose directly from the aorta. In 84% also there was at least one bronchial artery that supplied bronchi of both lungs.Arteries arising high on the anterior or right lateral surface of the aorta were found in more than one‐half of the casts, more than three times as frequently as in previously reported

ISSN:0002-9106    

DOI:10.1002/aja.1001170103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1965

数据来源: WILEY

摘要:

AbstractWith the use of both the sensitive fluorescence method of Falck and Hillarp for the histochemical demonstration of monoamines at the cellular level and electron microscopy the synaptic terminals were studied in nucleus caudatus putamen, nucleus tractus solitarii and the substantia grisea periventricularis of the fourth ventricle. In all these regions numerous boutons of a size similar to the varicosities of the monoamine terminal exist. They form mostly synapses with dendrites. The boutons are more or less filled with either small (about 300–350 Å), medium sized (about 450 Å) or — but less commonly — large (about 550–600 Å) agranular vesicles. Larger (about 800–1,000 Å) granular vesicles are found in all three regions studied. In comparison to the agranular vesicles, however, they are practically always few.In animals treated with a large dose of reserpine or nialamide none of the different types of vesicles showed any obvious changes. It is concluded that the monoamine storage granules are not identical with the large granular vesicles, but that they, with the method used, appear as small, agran

ISSN:0002-9106    

DOI:10.1002/aja.1001170104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1965

数据来源: WILEY

摘要:

AbstractThe secretory cells of large axillary sweat glands from 12 normal adults were studied at the light and electron microscope levels, using techniques for localization of enzyme reaction product. The morphological and cytochemical characteristics of the plasma membrane and cell organelles (Golgi apparatus, lysosomes, mitochondria, endoplasmic reticulum, secretory granules) were observed. An interpretation of the secretory process was attempted. Most of the evidence spoke against the existence of an apocrine mechanism. Possibly some of the methods employed also could be used for the demonstration of hormone action on the LASG.

ISSN:0002-9106    

DOI:10.1002/aja.1001170105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1965

数据来源: WILEY

摘要:

AbstractThe fate of the cells of the stratified squamous epithelium of the esophagus was investigated radioautographically in young adult rats at various time intervals after a single injection of thymidine‐H3.Soon after injection, labeled cells appeared in the basal layer of the epithelium (stratum basale). During the following 12 hours, the labeled cells completed DNA synthesis and mitosis, and mostly remained in the basal layer. After 12 hours, however, the labeled cells arising from the mitoses were transferred to the spinous layer (stratum spinosum) at the rate of 1.2% per hour.The respective fates of the two daughter cells of a mitosis were then examined using two‐dimensional maps showing the location of the labeled nuclei at 24 and 48 hours after injection. It was assumed that any two nuclei located side by side and overlaid by a similar number of grains are the two daughter cells of a mitosis. Such pairs of labeled daughter cells fell into three categories: (1)Basal pairs, composed of two basal cells; (2)Outgoing pairs, composed of two spinous (or granular) cells; and (3)Mixed pairs, composed of one basal and one spinous (or granular) cell. Since three possibilities were encountered at the two time intervals, the mitoses could not be differential (in which case the pairs of daughter cells would consist of a cell remaining in the basal layer and another migrating to the spinous layer, that is, all pairs would be “mixed”). Instead, the frequency of the three types of pairs was such as to indicate that the transfer of a basal cell to the spinous layer is a chance event which can affect any basal cell (except those undergoing DNA synthesis or mitosis). Accordingly, the transfer of either or both daughter cells of a mitosis would also be due to chance.The transfer of a cell out of the basal layer is a critical step in the life of the cell, since it precludes further division and appears to trigger differen

ISSN:0002-9106    

DOI:10.1002/aja.1001170106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1965

数据来源: WILEY

ISSN:0002-9106    

DOI:10.1002/aja.1001170107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1965

数据来源: WILEY

摘要:

AbstractThe cytological changes occurring in the epithelium of the mouse seminal vesicle between 5 and 49 days of postnatal life have been traced by electron microscopy.Initially the epithelium was composed of typical immature columnar cells. During the second week of life, the principal changes were: rapid cell proliferation, followed by increases in the amounts of organized ergastoplasm and Golgi material. During the third week, dense secretory material appeared in Golgi cisternae and then in the lumen of the gland.The parallelism between these changes and those found in maturing pancreatic acinar tissue has been assessed. Comment is made on the attachment of ribosomes to endoplasmic reticulum in the initiation of protein‐secretory activity, and the importance of the subsequent proliferation of ergastoplasmic and Golgi membranes. The evidence for relating these cytological and secretory alterations in the seminal vesicle to a rising titer of androgen during the prepuberal period has been cited.Other observations included: (a) Evidence for a considerable amount of cellular sloughing and resorption during the first two postnatal weeks; (b) an association of mitochondria with developing desmosomes, and (c) the appearance of basal cells first during the second week of postnatal life, thus suggesting that they arise by dedifferentiation of columnar cell

ISSN:0002-9106    

DOI:10.1002/aja.1001170108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1965

数据来源: WILEY

摘要:

AbstractThe Golgi complex consists of a heterogeneous assemblage of small vesicles, larger vacuoles and characteristic packets of flattened cisternae morphologically distinct from other membranous organelles of the cytoplasm. It is polarized with respect to its position in the cell and also shows recognizable polarity in the arrangement of structural components within the complex. This polarity holds for cells in which the Golgi complex seems to have quite different functions, such as in the epithelial cells of mouse epididymis and of Brunner's gland, and plasma cells in the lamina propria of the intestine examined in this study. The present investigation employs a classical method for impregnation of the Golgi apparatus with the objective of more accurately localizing with the electron microscope the sites of osmium reduction within this heterogeneous organelle and of comparing the distribution of these sites with morphological indications of polarization within the Golgi lamellar systems. The osmium impregnation procedure generally used in this study consisted of fixing the tissues in 1.3% osmium tetroxide buffered with s‐collidine followed by osmication in 2% aqueous osmium tetroxide for 40 hours at 40°C. After osmication the three cell types studied consistently exhibited a selective localization of osmium in the cisternae and vesicles on one side of the Golgi complex. The observations that only the outer vesicles and cisternae contain osmium while other cytologically similar elements under the same conditions do not, emphasizes the heterogeneous, bipolar nature of the Golgi apparatus. The substances responsible for osmium reduction are quite dependent on the local environment provided are apparently formed during the prolonged phase of the exposure of the tissue to osmium and are most likely localized at the inner face of the membrane of the outer cisternae and vesicl

ISSN:0002-9106    

DOI:10.1002/aja.1001170109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1965

数据来源: WILEY

摘要:

AbstractThe ϵ‐amino groups of reconstituted collagen were treated in a variety of ways and the collagen implanted subcutaneously in rats. After two weeks the implants were removed and examined histologically. A giant cell response was seen around the collagens treated with 1‐fluoro‐2,4‐dinitrobenzene, p‐nitrobenzoylchloride or carbobenzoxychloride, but not with the other reagents. Parallel experiments with autogenous bone, treated with the same methods, were carried out. A mild giant cell response was found in the untreated bone, but was enchanced only in bone treated with the same three reagents. It would appear that the giant cell response was greatly increased when the attached benzene ring had nitro groups in the para position, and also when there was an ester linkage in the attached radicle. It is unlikely that this reaction was immunological in character. The giant cells have many of the properties of osteoclasts. It is suggested that it is the nature of the organic matrix of bone that determines if osteoclasis s

ISSN:0002-9106    

DOI:10.1002/aja.1001170110

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1965

数据来源: WILEY

ISSN:0002-9106    

DOI:10.1002/aja.1001170101

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1965

数据来源: WILEY